Lifting mechanism of a window shade

ABSTRACT

A lifting mechanism of a window shade includes a cord retrieving and winding device which is disposed at the end of the window shade and includes an upper seat, a lower seat and a supporting rail, wherein the heights of two sides of the lower seat are outwardly decreased, and two protrudent portions are extended from two sides, and two protrudent portions of the upper seat and the lower seat are covered to each other, and two supporting rails are mounted in the two protrudent portions of the upper seat; and two tubes which are put around the two protrudent portions to form the lifting mechanism. Therefore, the lifting mechanism supports the cord retrieving and winding device by putting two tubes around two sides of the cord retrieving and winding device, and the curtain slats of the window shade cannot be oblique when the window shade is drawn and released.

FIELD OF THE INVENTION

The present invention relates to a lifting mechanism of a window shade, and more particularly to a lifting mechanism which supports the cord retrieving and winding device by putting the two tubes around two sides of the cord retrieving and winding device, and the curtain slats of the window shade cannot be oblique when the curtain slats of the window shade are drawn and released.

BACKGROUND OF THE INVENTION

Pull cords are generally utilized to remove a conventional window shade upward and downward. The pull cord is often exposed out of the window shade, and thus the exposed pull cord is a potential safety hazard to a playful child who may be accidentally strangled by the pull cord. For above reason, general user considers the problem of safety and gathers the pull cords to a cord retrieving and winding device of a lower rail so as to avoid exposing out the pull cords and resulting in the safety hazard.

Recently, the cord retrieving and winding device of the conventional window shade which is sold in the market is shown in FIG. 1 (i.e. the disclosure in U.S. Pat. No. 6,024,154). The cord retrieving and winding device A includes more components and is deposed in the interior of the lower rail B1, and thus the lower rail B1 is designed to have a bigger volume for receiving the cord retrieving and winding device A including more components. According to the lower rail B1 in whole, the whole assembly of the cord retrieving and winding device A is too big and the lower rail B1 must have a bigger volume. The cord retrieving and winding device A occupies larger space during assembly, wastes the cost, and increases the weight of the lower rail B1 so as to be not light and handy. Invisibly, springs are disposed in the interior of the cord retrieving and winding device A, wherein the work lifetime of the springs is decreased because the springs take larger force.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve the above-mentioned disadvantages, wherein the whole assembly of the cord retrieving and winding device is too big and the lower rail must have a bigger volume, and the cord retrieving and winding device occupies larger space during assembly, increases the weight of the lower rail, and wastes the cost. A lifting mechanism of a window shade is designed to include a cord retrieving and winding device mainly including an upper seat and a lower seat, wherein the heights of two sides of the lower seat are outwardly decreased, and two protrudent portions are extended from the two sides, whereby the thickness and weight of the cord retrieving and winding device are decreased, springs which are disposed in the interior of the cord retrieving and winding device take smaller force, such that the whole cord retrieving and winding device is light and handy and is directly disposed at the bottom of the lifting mechanism at the end of a window shade.

The present invention provides a lifting mechanism of a window shade including a cord retrieving and winding device and two tubes. The cord retrieving and winding device is disposed at the end of the window shade and includes an upper seat, a lower seat and two supporting rails, wherein the upper seat and the lower seat are respectively provided with two protrudent portions disposed at two sides thereof and covered to each other, and the supporting rails are mounted in the two protrudent portions of the upper seat. The two tubes are put around the two protrudent portions to form the lifting mechanism, whereby the lifting mechanism supports the cord retrieving and winding device by putting the two tubes around two sides of the cord retrieving and winding device, and the curtain slats of the window shade cannot be oblique when the curtain slats of the window shade are drawn and released.

The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view showing a window shade disclosed in U.S. Pat. No. 6,024,154.

FIG. 2 is an exploded perspective view of a lifting mechanism of a window shade of the present invention.

FIG. 3A is a perspective view of a window shade of the present invention.

FIG. 3B is a cross sectional view along line 3B-3B of FIG. 3A.

FIG. 4 is a schematic view showing a window shade of the present invention when the curtain slats are drawn and released.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 2 and 3A, they depict a basic structure of a lower rail of a window shade of the present invention. A cord retrieving and winding device 1 is directly disposed at the end 20 of the window shade 2. Two pull cords 21, 22 located at two sides of the window shade 2 are respectively gathered in the cord retrieving and winding device 1. Two tubes 3 are respectively put around two sides of the upper seat 10 and lower seat 11 of the cord retrieving and winding device 1 so as to form the lifting mechanism 4.

Referring to FIG. 3B simultaneously, the upper seat 10 is rectangular and two sides 100 of the upper seat 10 are respectively shrunk to be flat. Two protrudent portions 101 are extended from the two sides 100 and have corresponding bending edges 102, respectively. A snap edge 103 is formed between each protrudent portion 101 and side 100 of the upper seat 10. The two sides 100 and the protrudent portions 101 are respectively provided with locking holes 104, 105 located at the center thereof for turning screw elements 107 into the locking holes 104, 105. The protrudent portions 101 are provided with deep holes 106 located at the outward edge thereof.

The heights of two sides 110 of the lower seat 11 are outwardly decreased, and two protrudent portions 111 are extended from the two sides 110 and have corresponding bending edges 112, respectively. The two sides 110 are provided with locking rods 113 located at the outward edge and corresponding to the deep holes 106 of the upper seat 10. The locking rods 113 are provided with screw holes 114 for turning screw rods 108 into the screw holes 114 to be mounted.

Two supporting rails 12 are provided with screw holes 1200 located at one side thereof and corresponding to the locking holes 104, 105 of the upper seat 10. The supporting rail 12 is further provided with a sliding rail 120 located therein. The sliding rail 120 is provided with a corresponding guide pulley 121 disposed at the outward edge thereof. The sliding rail 120 is further provided with pull cord 21, 22 disposed therein, whereby the guide pulley 121 guides the pull cords 21, 22.

The tube 3 has a hollow and flat shape 30 and is provided with a through hole 31 corresponding to the guide pulley 121 disposed at the outward edge of the sliding rail 120.

During assembly, the cord retrieving and winding device 1 is directly adhered to the end 20 of the window shade 2, whereby the two pull cords 21, 22 located at two sides of the window shade 2 are respectively guided by the guide pulley 121 of the lower seat 11 and are gathered at the winding region 130 of two spring retrieving pulley 13 in the cord retrieving and winding device 1. Moreover, the supporting rails 12 are mounted by turning the screw elements 107 into the locking holes 104, 105 of the protrudent portions 101 of the upper seat 10, whereby the two pull cords 21, 22 are retrieved and released by the sliding rail 120 located in the supporting rail 12, and then the two pull cords 21, 22 are guided to pass through the through hole 31 of the tube 3 by the guiding pulley 121. Each curtain slat 23 is serial connected to one another by the two pull cords 21, 22, and the protrudent portions 101 of the upper seat 10 and the protrudent portions 111 of the lower seat 11 are covered and mounted to each other, whereby the tubes 3 with the hollow and flat shape 30 are put around the protrudent portions 101, 111 of the upper seat 10 and the lower seat 11 to form an integral shape of the lifting mechanism 4, wherein the lifting mechanism 4 supports the window shade 2 by putting the two tubes 3 around two sides of the cord retrieving and winding device 1.

Referring to FIG. 4, when the curtain slats 23 of the window shade 2 are drawn and released during operation, the lifting mechanism 4 supports the cord retrieving and winding device 1 by putting the two tubes 3 around two sides of the cord retrieving and winding device 1. In other words, the curtain slats 23 of the window shade 2 cannot be oblique because of the lifting mechanism 4.

Although the invention has been explained in relation to its preferred embodiment, it is not used to restrain the invention. It is to be understood that many other possible modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention as hereinafter claimed. 

1. A lifting mechanism of a window shade comprising: a cord retrieving and winding device disposed at the end of the window shade and including an upper seat, a lower seat and two supporting rails, wherein the upper seat and the lower seat are respectively provided with two protrudent portions disposed at two sides, thereof and covered to each other, and the supporting rails are mounted in the two protrudent portions of the upper seat; and two tubes put around the two protrudent portions to form the lifting mechanism, whereby the lifting mechanism supports the cord retrieving and winding device by putting the two tubes around two sides of the cord retrieving and winding device, and the curtain slats of the window shade cannot be oblique when the curtain slats of the window shade are drawn and released.
 2. The lifting mechanism of a window shade according to claim 1, wherein the upper seat is rectangular and the upper seat has two sides being respectively shrunk to be flat.
 3. The lifting mechanism of a window shade according to claim 2, wherein the two protrudent portions are extended from the two sides and have corresponding bending edges respectively, and the upper seat includes a snap edge formed between each protrudent portion and side of the upper seat.
 4. The lifting mechanism of a window shade according to claim 2, wherein the two sides of the upper seat and the protrudent portions are respectively provided with locking holes located at the center thereof, the protrudent portions are provided with deep holes located at the outward edge thereof, and the supporting rails are mounted by the locking holes.
 5. The lifting mechanism of a window shade according to claim 4, wherein the supporting rail is provided with a sliding rail, and the sliding rail is provided with a corresponding guide pulley.
 6. The lifting mechanism of a window shade according to claim 1, wherein the heights of two sides of the lower seat are outwardly decreased, and two protrudent portions are extended from the two sides of the lower seat and have corresponding bending edges respectively.
 7. The lifting mechanism of a window shade according to claim 6, wherein the two sides of the lower seat are provided with locking rods located at an outward edge and corresponding to the deep holes of the upper seat, and the locking rods are provided with screw holes.
 8. The lifting mechanism of a window shade according to claim 1, wherein the tube has a hollow and flat shape.
 9. The lifting mechanism of a window shade according to claim 8, wherein the tube is provided with a through hole corresponding to the guide pulley. 